Sometimes is wery complicated to install power points and to use power adapter on the place where equipment should be placed (as cameras and Wireless Access Points). Solution is to use UTP cables to pass electric power for equipment.
To do this we need or to have Power Network Switch or PoE Injector. Also, equipment must be with PoE inputs. Some swithes have option to send power on its ports. If we have switch without this option, or we does not wish to use switches as charger, then we can use PoE injector for this function, small peace of equipment hnich is placed on line between switch and powered device.
Up to 15.4 W / 37-57 V (PoE standard) or 25.5 W / 42.5 – 57 V (PoE plus) is available for a powered device (PD).
Red more:
Power over Ethernet
Power over Ethernet (POE) Explained
Examples
How to enable detection of a powered device and to automatically power a PoE port:
Switch(config)# interface fastethernet0/2
Switch(config-if)# power inline auto
How to configure a PoE port to allow a Class 1 or a Class 2 powered device:
Switch(config)# interface fastethernet0/2
Switch(config-if)# power inline auto max 7000
How to disable powered-device detection and to not power a PoE port:
Switch(config)# interface fastethernet0/2
Switch(config-if)# power inline never